Avatar: The Way of Water is set to release this December, but it has a pretty major problem: it’s a sequel to a film that came out 13 years ago. Meanwhile, most of us can barely remember what happened on last week’s episode of She-Hulk — when Avatar 2 hits theaters, there could be a lot of confusion if characters start talking about unobtanium, Toruks, RDA, or the Noble Clyde Boudreaux. (One of those things isn’t actually in the…